This last week I was talking to someone at a small startup that intends to eliminate all the complex routing from campus networks. In the past, when reading blog posts about Kubernetes, I’ve read about how it was designed to eliminate routing protocols because “routing protocols are so complex.”
Color me skeptical.
There are two reasons for complexity in a design. The first is you’re solving a hard problem. The second is you’ve made bad design choices in the past, and you’re pasting complexity on top to solve some perceived problem (whether perceived or real).
The problem with all this talk about building something that’s “less complex” is people tend to see complexity of the first kind and think, “we can get rid of that complexity if we start over.” Failing to understand the past before building the future is a recipe for repeated failures of the same kind. Building a network without a distributed routing protocol hasn’t been tried before either, right? Well, yes, it has … We either forget how it turned out, or we say “well, that’s not the same thing I’m talking about here” (just like “real socialism hasn’t ever been tried”).
Even worse, they think they get rid of second and third kinds of complexity by starting over, or getting the humans out of the decision-making loop, or focusing on the data. Our modern penchant for relying “the data,” without ever thinking about the source of the data or how the data has been shaped and interpreted, is truly breathtaking.
They look over the horizon, see an unspoiled field, and think “the grass really is greener on the other side.”
Get rid of all those complex dynamic routing protocols … get rid of all those humans making decisions, so the decisions are “data driven” … and everything will be so much better.
Adding complexity to solve hard real-world problems is just the way things are, and they will always be, so the first reason for complexity will always be with us. People make mistakes, don’t see into the future perfectly, or just don’t have a perfect understanding of the system (technical debt), so the second kind of complexity will always be with us. You can’t “fix” people—God save us from those who think they can. The grass isn’t always greener—it just always looks that way.
What’s the practical upshot? Networks are always going to be complex. It’s just the nature of the problem being solved.
We add complexity because we fail to ask the right questions, we don’t understand the system, or we fail to do good design. The solution isn’t to seek out a greener field “out there,” but rather to make the field we currently live in greener by asking the right questions and reducing complexity through good design. Sometimes you might even need to start over with a new network … but when you start thinking about starting over with a newly designed set of protocols because the old ones are “too complex,” you need to ask how those old ones got that way, and how you’re going to stop the new ones from getting to the same place.
The grass is always greener because you looking at it through green-colored lenses just as the new grass is in its full flush, and before the weeds have had a chance to take over.
Learn how old things worked before you fall for some new “modern wonder” that’s going to solve every problem. The complexity in old things will show you where you can expect to find complexity grow up in new things.